Alternative fuels such as natural gas, propane, ethanol, hydrogen, biodiesel, butanol, methanol, and P-Series fuels are becoming increasingly popular and are supplementing traditional fuels such as gasoline and diesel. Users select these alternative fuels for a variety of reasons. For example, a user may desire the most cost effective fuel, and different governments may offer incentives for a user to buy certain types of fuel. Further, a user may be constrained by geography since alternative fuels have varying availability in different locations. Therefore, a user may choose a certain type of fuel because of its availability in a particular area.
While some alternative fuels may be preferable in some instances, they may not be preferable in every situation. For example, a natural gas supply may experience pressure drops, pressure spikes, other service interruptions, and even quality issues such as inconsistent energy content (BTU). Further scenarios include prices of various fuels changing over time, government incentives expiring or beginning, and a change in location of an engine. Therefore, it is desirable for an engine to have the capability of using more than one fuel so that a user may optimize fuel consumption for minimal price, location, or any other parameters.
There have been some previous efforts that attempt to address the issue of fuel optimization. For example, U.S. Pat. No. 8,061,121, which is incorporated herein by reference in its entirety, envisions a system where a car tank may be filled with traditional gasoline or an ethanol blend. A sensor detects the amount of alcohol in the air-fuel mixture, and based on sensor's measurement the system adjusts whether to operate the engine conventionally at stoichiometry or in a lean combustion mode. In a further system, U.S. Patent Publication No. 2011/0114058, which is incorporated herein by reference in its entirety, contemplates a system with two tanks one tank filled with gasoline and one tank filled with natural gas. This system comprises specialized bi-fuel spark ignition engine that allows the engine to operate on gasoline, natural gas, or a combination of the two.
One limitation with the prior art is that it does not contemplate a user's desire to use as much primary fuel as possible even in the face of quality issues, quantity problems, or other similar concerns. While alternative fuels may hold certain advantages in certain instances, it may be desirable (e.g., cost effective) to use as much primary fuel as possible while dealing with quantity issues, etc. Further none of the primary art devices allow for an uninterrupted supply of fuel when one source of fuel is abruptly shut off. This limitation with prior art devices results in performance issues with the engine, for example, a reduction in engine speed or RPMs. Due to these limitations associated with the prior art and more, the following disclosure describes an improved multi-source gaseous fuel blending manifold.